Moving picture experts group (MPEG)-2 transport stream (TS) is a communication protocol for transmitting multimedia-related data including audio, video, data, and the like through a network. MPEG-2 TS is used for transmission of media data in terrestrial/satellite digital broadcasting, digital multimedia broadcasting (DMB), internet protocol television (IPTV), and the like, and also used for storing media in a digital video camera or a Blu-ray device.
However, as the broadcasting network and the communication network gradually converge and become advanced, new generation contents such as ultra high definition (UHD) video contents and 3-dimensional (3D) video contents and new services such as N-screen service are emerging in these days. As a result, new and various requirements arise.
Therefore, as the first part of MPEG-H (High Efficiency Coding and Media Delivery in Heterogeneous Environments) standard to provide various services such as digital broadcasting in various kinds of broadband communication networks, MPEG media transport (MMT) technology is being developed.
The MMT technology aims at providing functions of efficient multimedia data transmission and playback in various network environments that are being advanced. The MMT technology mainly includes a media processing unit (MPU) function area, a signaling function area, a delivery function area, and a presentation information area.
As an example of various network environments, user terminals that request media contents may access various kinds of networks such as a 3G mobile communication network, a 4G mobile communication network, a Wi-Fi network, a wired network, and the like, depending on their terminal types. Also, even the same user terminal may change accessing networks, e.g., from the 4G mobile communication network to the W-Fi network, depending on its location.
In addition, according to recent services, a user who is using specific content through a mobile communication terminal while moving may continuously use the same content through another user terminal, for example, a smart TV. Namely, in order to provide the same content, the user terminals as well as the networks may be changed.
In consideration of such network environments and service environments, effective transmission and playback of multimedia data may require data transmission in a suitable form according to the type of network connected to each user terminal. Further, even in case of the same user terminal, network-adaptive content transmission suitable for the network type is required during a service in view of a change of the network type caused by movement of the user terminal.